Wide-spectrum quinolones such as moxifloxacin and levofloxacin as well as high-order cephalosporins such as cefoperazone and cefepime have increased antimicrobial activity. However, little is known about their distribution in fetal blood. Therefore, the aim of this study was to measure and compare maternal and fetal blood levels of these agents. For the measurement of blood levels, 9 pregnant women received cefepime hydrochloride, 10 received cefoperazone, 10 received moxifloxacin and 12 received levofloxacin intravenously. Maternal and umbilical cord blood samples were drawn during delivery. Antibiotic levels were analysed by high-performance liquid chromatography. Mean transplacental passage rates of moxifloxacin, levofloxacin, cefepime and cefoperazone were 74.84%, 66.53%, 23.21% and 12.68%, respectively, and mean transfetal passage rates were 90.78%, 84.22%, 79.17% and 79.78%, respectively. The transplacental passage rate for either quinolone was significantly higher than that of either cephalosporin, and the transplacental passage rate of cefoperazone was lower than that of cefepime. In conclusion, both quinolones have high transplacental passage rates. Cefepime and cefoperazone have a lower transplacental passage rate and thus may be used as prophylaxis in situations where transplacental passage is undesirable.